Thermostatic circuit-closer.



PATENTEAD MAY 30, 1905.

A. D. CAYWOOD.

THBRMOSTATIG CIRCUIT CLOSER.

APPLIOATION FILED AUG. 12, 1904.

2 SHEETS-411E111 1.

2a 5 1 a 0 w i/ C @WWZZ PATENTED MAY 30, 1905.

A. D. GAYWOOD.

THERMOSTATIG CIRCUIT CLOSER.

APPLICATION FILED AUG 12 1904 2 SHEETS-SHEET 2.

I7z/U 7112 7': 666 r127 l ywaod, 2?? 4 UNITED STATES Patented May 30,1905.

ALBERT D. CAYIVOOD, OF CHICAGO, ILLINOIS.

THERMOSTATIC CIRCUIT-CLOSER.

SPECIFICATION forming part of Letters Patent No. 791,182, dated May 30,1905.

Application filed August 12, 190d. Serial No. 220,511.

To all whom it may concern:

Be it known that I, ALBERT D. OAYWOOD, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a new and useful Thermotic Circuit-Controller, of which thefollowing is a specification.

My invention pertains particularly to means for controlling an electriccircuit of a fire-alarm system; and my primary object is to provide athermotic circuit controller possessing great certainty of operation andfree from liability of corrosion or injury from external influences orcauses.

The invention is illustrated in the accompanying drawings, in whichFigure 1 is a sectional view of my improved device for use in a normallyopen circuit be fore the terminals have been connected with thecircuit-wires and cemented in place, the section being taken asindicated at line 1 of Fig. 2; Fig. 2, a top plan View after thecircuit-wires have been connected; Fig. 3, a section similar to thatshown in Fig. 1, but showing the terminals covered with cement andillustrating the condition after opera tion Fig. 4, a perspective viewof the internal parts and the top plate of the device shown in thepreceding figures; and Fig. 5, a sectional view illustrating a modifiedconstruction for use in a normally closed circuit.

A description of the preferred construction for use in a normally opencircuit is as follows: A represents an external casing, which may be ofporcelain, said casing having an external flange (0 and a vertical borea, stepped. to provide annular internal shoulders or steps (L2 a, thereduced lower end. of said bore being also countersunk or chamifered, asindicated at a"; B, an internal casing or barrel comprising a disk 1),bearing on the shoulder a and having a downwardlyextendingbarrel-section b and a ring or barrel section 7), upon which thebarrel-section Z) is supported; C, a contact member located between theinner and outer casings; C, a contact member confined within the innercasing or barrel; C", a cap having solder connection with the dishedperforate portion of the member C; D, a celluloid washer supported onthe shoulder a and in turn supporting the member C; D, a celluloid capfitting onto the depressed central portion of the washer D, and E aninsulating-ring supported by the cap C and normally serving to hold thecontact member C out of engagement with the member C. The casing A isprovided at its flange a with perforations for receiving screws, bymeans of which the device may be attached to a ceiling or wall. The diskI) of the inner casing fits within the enlarged upper end of theexternal casing and constitutes a closure for the outer casing, beingsecured by means of screws, as shown. The contact member C comprises awasher having a downwardly-dished central portion and provided at itsperiphery with a terminal 0, which extends upwardly through a channelbetween the barrel B and the wall of the bore a and protrudes through anopening 0 in the flange, forming portion of the disk I). The dished orconical portion of said last-named washer lies beneath the bore of theinner barrel B. The contact member C comprises a stem 0 extending intothe upper portion of the insulating-ring E, and a toothed metallicmember 0 fixed thereon and bearing on the ring E, and a cone-spring c,confined be tween the member 0 and disk I) and having a terminal orextension 0 protruding through a perforation c in the disk I). Therelatively large upper end of the conespring is in substantial contactwith the inner wall of the barrel-section Z), and the toothed member 0is in substantial contact with the inner wall of the barrel-section 5 sothat the inner contact member 0 is properly centered and guided. Asalready indicated, the member a normally is held out of contact with thedished portion of the member C by means of the insulation E, resting onthe soldersupported cap C The terminals 0 (f are bent over above thedisk I) and connected with circuitaviresfj", as shown in Fig. 2. The topsurface of said disk lies below the upper sur face of the casing A, andthat portion of the bore (1. which lies above said disk is filled withcement f thereby embedding the terminals. The cap C is sheathed by thecap D, and thus the whole device is neat in appearance and free fromdanger of corrosion. The cap D lies within the countersink at the loweror outer end of the bore a and isfree from injury. It now will beunderstood that when subjected to heat of predetermined degree thesolder will loosen, permitting the spring to force the member 0 intocontact with the member 0, thereby completing the circuit through thecontact members 0 and C. When this action occurs, the caps C and D andthe member E drop, as shown in Fig.

' 3, assuming, of course, that the heat has not been sufficient todestroy the celluloid ca which cap in any event does not prevent t eheat from readily fusing the solder supporting the cap C In theconstruction for normally closed circuits (shown in Fig. 5) A representsthe outer casing, and B the inner casing. The remainder of theconstruction is the same as that already described, except that theinsulation E is dispensed with, the metallic member c is replaced byaninsulating-washer c and the stem of the contact member C bearsdirectly on the metallic cap C In this construction it is noted that thesection of Fig. 5 is at right angles to the section of Fig. 3, whichaccounts for the failure to show the terminals in the same manner. It isevident that when the cap C is forced from its place the connection willbe destroyed, the washer 0 operating to keep the stem centered and outofcontact with the dished portion of the contact member C.

It is noteworthy that the two constructions shown possess the samefeatures of advantage as regards neatness and security of housing andcertainty of operation, and it will be understood that variousmodifications of construction within the spirit of the invention so faras it pertains to these common features of construction may be madewithout departure from my invention.

From the foregoing it will be understood that no undue limitation is tobe understood from the foregoing detailed description.

What I regard as new, and desire to secure by Letters Patent, is

1. The combination of an outer casing, a contact member therein, aninner casing, a

potentially-movable contact member therein and separated from the outercontact memher by the walls thereof, and fusible means normallyrestraining the inner contact member from movement, for the purpose setforth.

2. The combination of an outer insulationcasing having a bore extendingtherethrough, a contact member therein, an inner two-partinsulation-casing having a bore closed at one end, an inner contactmember with a coilspring for effecting movement, the outer contactmember projecting into the path of the inner contact member, and fusiblemeans normally restraining the inner contact member from movement,' forthe purpose set forth.

3. The combination of an outer insulationcasing having a bore withportions'of successively-reduced diameter, forming internal shoulders, acontact member therein, an inner insulation-casing conforming to thebore of the outer casing, and an inner contact member with a coil-springconfined in the inner casing, fusible means serving normally tohold thespring under tension being included in the construction, for the purposeset forth.

4. The combination of a casing having a bore 0, provided internally withshoulders a a a contact member having a washer sup ported from theshoulder a an inner casing with a closed top, a contact member inclosedby the inner casing, and fusible means serving normally to preventmovement of the inner contact member, for the purpose set forth.

5. The combination of a casing having a stepped bore, a contact memberhaving a washer supported from one step of the bore, a solder-supportedcap connected with said washer, a non-corrosive cap protecting saidfirst-named cap, an inner insulation-casing, and a spring-equipped,normally restrained contact member within the inner casing, for thepurpose set forth.

6. The combination of a casing having a stepped bore, a celluloid washersu ported on one step of the bore and having flle central portion struckdownwardly, a celluloid cap removably connected with the struckdownportion of said washer, a contact member having a washer bearing on saidfirstnamed washer, a cap having solder connection with said second-namedwasher, an inner casing of insulating material, and a contact memberconfined within said inner casing and equipped with a spring, the innercontact member being held normally under restraint, for the purpose setforth.

7. The combination of a casing having a stepped bore, a contact membertherein, an inner casing having a closed end located beneath the uppersurface of the outer casing, a spring-equipped contact member within theinner casing, terminals leading from the contact members to the spaceabove the top of the inner casing, wires connected with said terminals,cement filling above the top of the inner casing closing the bore of theouter casing at one end, a solder-supported member connected with thefirst-named contact member and serving normally to hold the secondnamedcontact member against movement, and a non-corrosive removable memberprotecting said solder-supported member, for the purpose set forth.

8. The combination of an outer casing, a contact member supportedtherein, an inner two-part casing having a top disk, a contactInemberconfined within said inner casing, and terminals leading fromsaid contact members on one step thereof, an inner two-part casingprovided with a closed top asolder-supported member connected with saidcontact mem ber, an inner contact member comprising a cone-spring and astem connected with the small end thereof and a toothed member connectedwith said stem, and an insulationwasher carried by the soldersupportedmember and serving normally to hold said toothed member out of contactwith said first-named contact member, substantially as and for thepurpose set forth.

ALBERT D. CAYlVOOD. In presence of- L. HEIsLAR, WALTER N. WINBERG.

